John Lyall :: Department of Conservation
1. Introduction
Qualifications and Experience
1.1 My name is John Lyall. I am employed by the Department of Conservation in Hokitika as a Technical Support Officer, Terrestrial Fauna. My role is to provide advice on the management of threatened terrestrial species and I have worked in this advisory role on the West Coast since 1990. I am currently a member of the Kiwi, Mohua, and Blue Duck Recovery Groups and leader of the Bat and Westland Petrel Recovery Groups. Recovery Groups are national groups of technical specialists that provide advice on management of a particular species. I have worked with several species of kiwi including great spotted kiwi. My qualifications include a Bachelor of Science and a Diploma in Parks and Recreation Management with Distinction.
Summary of evidence
1.2 I have reviewed the Resource Consent Applications and Assessment of Environmental Effects, and various ecological reports and management plans provided by the applicant. I have also visited the site on two occasions and during the second visit camped a night adjacent to the application area. My evidence relates only to great spotted kiwi.
My evidence has been peer reviewed by the following Department of Conservation employee:
Dr Hugh Robertson; Kiwi Recovery Coordinator (Research & Monitoring),
2. The Evidence - Great Spotted Kiwi
2.1 Great spotted kiwi are found only in the South Island, roughly north of Hokitika, and mainly in the western and central parts of the island (Heather & Robertson 2000).
2.2 The three major populations for the species are in: northwestern Nelson, in the Paparoa Ranges, and in the Southern Alps from the Hurunui River to Arthur’s Pass (Heather & Robertson 2000).
2.3 The current distribution is a remnant of past distribution.
2.4 The latest population estimate is 20,000 birds (Heather & Robertson 2000) based on McLennan and McCann’s (2002) estimate of 22,000 birds in the mid-1990s.
2.5 There are currently 6 recognised taxa of kiwi including great spotted kiwi. Population estimates of each taxa as at 1996 are North Island brown kiwi 35000, rowi 150, Haast tokoeka 225, Southern tokoeka 27000, and little spotted kiwi 1100 (Robertson 2003a).
2.6 Great spotted kiwi are classified as in ‘gradual decline’ in the Department of Conservation’s threat classification system (Hitchmough 2002a).
2.7 The major threat to the survival of great spotted kiwi on the mainland is believed to be predation of chicks/juveniles by stoats (Mustela erminea) (McLennan et al 1996).
2.8 Generally for kiwi to survive on the mainland they need large areas of habitat and relief from predation of chicks by stoats, and predation of adults by dogs and ferrets.
2.9 Controlling stoats is usually carried out by using extensive networks of traps over large areas.
2.10 There is currently no predator control on the West Coast to specifically protect great spotted kiwi.
2.11 Department of Conservation monitoring in the Denniston area has shown a 5% decrease in call rate per annum over the last 6-7 years (Robertson 2003b).
2.12 To maintain a population of kiwi on the mainland, control needs to be undertaken over 5000 ha within a 10000 ha tract of forest (Basse and McLennan 2003). This is considerably larger than the size proposed by Dr McLennan for mitigation because it is to maintain a population compared with offsetting the impacts of the loss of 10 or so adults.
2.13 A strategy of stoat control in the kiwi sanctuaries through extensive (10,000+ ha) trapping is already in place on the West Coast at Okarito and Haast to protect rowi and Haast tokoeka respectively.
2.14 There are three other kiwi sanctuaries at Moehau (Coromandel), Tongariro and Whangarei, and many other sites where kiwi protection is being undertaken.
2.15 The initial strategy in the kiwi sanctuaries has been to focus on the most threatened taxa first and determine the effectiveness of management techniques in these. When further funds become available, other kiwi taxa, including great spotted kiwi, can be protected with effective management methods.
3. The Evidence - The Application
3.1 The development of the pit and loss of habitat is likely to be catastrophic for the approximately 10 adult great spotted kiwi estimated to be living within the pit area.
3.2 I agree with the assessment of great spotted kiwi (10 or so adults) within the application area as noted on page 213 of the AEE.
3.3 I agree with the assessment of kiwi (approximately 100) within the mining permit area and assessment of the number of birds (1800) in the area covered by the Mt William Range, Orikaka River, the western slopes the Glasgow Range and the Ngakawau River catchment and Buller Ecological Districts on page 214 of the AEE.
3.4 I agree with the assessment of the possible effects of the mine on great spotted kiwi on pages 289-293 in the AEE.
3.5 I note and concur with the following comments on page 293 of the AEE: “By other measures the kiwi in the Mt William Range have a conservation significance that exceeds their numerical importance. The Mt William kiwi inhabit, relatively speaking a natural refuge, where the impacts of stoats are less severe than those experienced by great spotted kiwi in some other parts of their range”. Further in the paragraph it continues “The populations in the natural refuges are expected to persist for longest and to progressively increase in conservation status as those in other areas disappear. Such populations are therefore worthy of special protection, and every effort should be made to prevent avoidable losses, irrespective of the number of individuals involved”.
4. The Evidence - Mitigation
4.1 Two programmes of mitigation are recommended by Dr McLennan in the great spotted kiwi management plan: removal of the great spotted kiwi from within the pit area and predator control in adjacent habitat.
4.2 I am uncertain whether transferring the kiwi away from the pit is the best approach as the technique is unproven for great spotted kiwi.
4.3 As the habitat is removed the kiwi will compete with adjacent pairs for the remaining habitat with the potential to disrupt the adjacent pairs breeding. This further compounds the effect of the mine on great spotted kiwi and there is a risk that kiwi may die in disputes over territories.
4.4 These disruptions to breeding may occur over a short timeframe, e.g. several months to a year.
4.5 If great spotted kiwi are not removed, and when the disputes for territories have been settled, then these 10 or so kiwi will probably still be able to breed within the nearby area. There may need to be some actions required to ensure that kiwi are not crushed during land development if they are to be left on site.
4.6 If the great spotted kiwi are not removed, then the funds that would be used to transfer and monitor them post transfer could be available to improve or extend the predator control.
4.7 Removal of kiwi will require approval of the Minister of Conservation under the Wildlife Act 1953 and would require input from Department of Conservation staff on methods of capture, transfer, release site and monitoring.
4.8 I agree with Dr McLennan’s recommendation to undertake predator control, as stated previously in my evidence; to maintain great spotted kiwi on the mainland it is essential to reduce predation of chicks by stoats.
4.9 Predator control to protect other species of kiwi on the West Coast has had limited success.
4.10 It has not achieved the necessary levels of chick survival for the population to maintain itself in years when predator numbers irrupted in response to heavy fruiting of canopy trees. At Okarito it has perhaps been effective one year out of three, and in Haast the sample sizes are too small to be able to draw a robust conclusion about the effectiveness of trapping stoats throughout a 10,000+ ha area.
4.11 In years when predator control has been ineffective the Department of Conservation has supplemented predator control with removal of chicks to a predator free environment until the chicks are of a sufficient size that stoats do not prey upon them. When they reach this size they are released back in to the forest.
4.12 Neither predator control programme has been running long enough to determine if the technique will be effective over a long period of time, and several more years of testing are required.
4.13 Similar forest fruiting events can be expected in the area recommended for predator control by Dr McLennan. Such fruiting events may lead to irruptions in predator numbers.
4.14 There are some major differences in the predator control proposed by Dr McLennan and the current “best practice” adopted by the Department of Conservation.
4.15 The predator control recommended by Dr McLennan has a trap density of one trap tunnel per 1.25 ha compared to trap tunnel densities of one per 9.1 ha in the rowi sanctuary at Okarito and one per 15 ha in the Haast tokoeka sanctuary though this does not mean that it will catch more stoats.
4.16 The kiwi sanctuaries in Okarito and Haast are 10000 ha and 11400 ha respectively compared to the 1000 ha recommended by Dr McLennan. The 1000 ha proposed is only 20% of the size of the area recommended by Basse & McLennan (2003) to maintain a kiwi population.
4.17 The kiwi sanctuaries at Haast and Okarito do not have rat control (other than those caught in stoat traps) whereas Dr McLennan has recommended the use of toxins to control rats in the area being managed for great spotted kiwi.
4.18 Rat control may be beneficial in improving survival of great spotted kiwi chicks, because rats are likely to be the main prey of stoats in the area, and they may also complete with kiwi for food.
4.19 The habitat characteristics of the existing kiwi sanctuaries and the site proposed for predator control are not comparable.
4.20 I agree with Dr McLennan’s recommendation to implement a predator exclusion area for chicks as experience has shown that in years of high predator numbers trapping may not be effective. The use of an enclosure could substantially improve the ability of the mitigation to produce chicks to a stoat- proof size. This could be used in lieu of an offshore island as described previously in my evidence. To effectively implement a programme to do this would require transmitters attached to the adults.
4.21 It is unknown whether the predator control proposed by Dr McLennan will be effective in increasing chick survival to the level needed to offset the impacts of the mine at this site. I note that predator control at this intensity on a site of similar size in the North Island significantly improved Brown Kiwi survival (McLennan et al in prep.). However, it should be noted that this was on a peninsula with limited opportunities for stoats to re-invade, and that brown kiwi are much more productive than great spotted kiwi (i.e. they produce about 2 - 3 times as many chicks each year).
4.22 I agree with Dr McLennan’s recommendation to upgrade the programme if it is not proven to be effective. The exact nature of the upgrade can only be determined after the initial programme has been trialled.
4.23 I agree with Dr McLennan’s recommendation to monitor the outcomes of the predator control and upgrade it after the first 5 years after implementation if it is proven not to be effective.
5. The Evidence - Conclusion
5.1 The application will have an impact on the 10 or so great spotted kiwi within the pit and perhaps some adjacent pairs.
5.2 At a national population level this impact is insignificant.
5.3 With effective mitigation the impacts on great spotted kiwi can be offset; however, it is unknown if the proposed mitigation will produce any benefit for the local population of great spotted kiwi.
5.4 The effectiveness of the proposed programme should be scientifically evaluated after 5 years, and mitigation efforts increased if it can not be shown that the management has increased the numbers of great spotted kiwi.
References
Basse, B.; McLennan, J.A. 2003. Protected areas for kiwi in mainland forests of New
Zealand: how large should they be? New Zealand Journal of Ecology 27: No. 2, 2003.
Heather, B.D.; Robertson, H.A. 2000. The Field Guide to the Birds of New Zealand (Revised Edition) Viking, Auckland.
Hitchmough, R. (compiler) 2002a. New Zealand threat classification system lists—2002. Threatened species occasional publication 23. 210 pp.
McLennan, J.A. 1992. Nationwide monitoring of kiwi populations. DSIR Land Resources. Contract Report No 92/21 for Director, Science & Research, Department of Conservation, Wellington. 16 p.
McLennan, J.A.; Dew, L; Miles, J.; Gillingham, N; Waiwai, R; Stevenson, R; Billing, T; Winitana, R; Tekurupa, T. 2004. Response of northern brown kiwi to restoration management at Lake Waikaremoana, NZ. New Zealand Journal of Ecology in prep.
McLennan, J.A, McCann, A.J. 1991. Ecology of great spotted kiwi, Apteryx haastii. Contract Report No. 91/48 for Director, Science and Research, Department of Conservation, Wellington. 39 p.
McLennan, J.A, McCann, A.J. 2002. Genetic variability, distribution and abundance of great spotted kiwi (Apteryx haastii) in Overmars, F. 2002 (Ed.) Some early studies on kiwi (Apteryx spp.) genetics and management. Science and Research Internal Report 191, Wellington.
McLennan, J.A.; Potter, M.A.; Robertson, H.A.; Wake, G.C.; Colbourne, R.; Dew, L.;
Joyce, L.; McCann, A.J.; Miles, J.; Miller, P.J.; Reid, J. 1996. Role of predation in the decline of kiwi, Apteryx spp., in New Zealand. New Zealand Journal of Ecology 20: 27-35.
Robertson, H.A. 2003a. Kiwi (Apteryx spp.) recovery plan 1996 – 2006. Threatened Species Recovery Plan 50. Wellington, Department of Conservation. 26 p.
Robertson, H.A. 2003b. Research and monitoring report and recommendations to the 2003 Kiwi Recovery Group meeting. Internal Department of Conservation report.
